Synchronisation (“synching”) is the manipulation of the oestrus cycle through the use of naturally-occurring hormones, to enable a group of animals to be served on the same day. After synching, cattle will commonly be served through AI, although natural service is possible.
The benefits of the resulting tight calving period may include:
- Ease of observation at calving – knowing within a few days exactly when calves are likely to make an appearance.
- Informed housing/feeding/staffing decisions based on accurate predicted calving dates.
- Little variation in the age of calves when it comes to routine tasks (e.g. disbudding, worming and weaning) and reducing the age difference between pen mates, which can cause problems
- Closer monitoring of individuals – if a calf is falling behind, it can be easier to spot
How else might synching benefit a herd?
- Genetics – AI using sexed semen can introduce new genetics via replacement animals. Conception rates are generally better in heifers and your youngest animals are also likely to be your best genetically, so generally these are the best candidates for AI to breed your future females.
- Closed herd – when a bull’s daughters are coming through, the choice is often between buying a new bull or buying in replacements. From a biosecurity and disease perspective, buying in represents a risk and should be avoided where possible.
- Heifers – synching can be used to advance the breeding season in heifers, prior to the rest of the herd going to the bull: this gives them and their calves a head start during the early lactation period
- Cost – AI that requires a visit for each cow has become much more expensive recently- serving a group of animals in one go results in far fewer visits and any costs associated are known ahead of the service period
- No need for bulls – it can be useful where the benefits of running a bull are outweighed by the disadvantages (e.g. health and safety risks or housing). This may be particularly relevant in smaller herds.
So what does it involve and is it suitable for my farm?
To maximise conception rates, cattle must be in good body condition and on a rising plane of nutrition. This is even more important with synching than with natural service. Heifers must be at least 65% of mature cow body weight and have had at least one heat prior to starting the program. Cows must be condition score 2.5-3, depending on breed.
There are lots of different protocols out there – you and your routine vet will decide on a bespoke program to suit the enterprise. All programs will start with a scanning visit by a vet to assess uterine health and ovarian activity; subsequent injections and AI can be carried out by one of our vet techs or by your own staff.
The ability to handle the group frequently, easily and without stress (to cattle or handlers!) is a prerequisite: all protocols will require a few injections at set intervals, plus single or double AI. It is vital that once a synch programme is started, that the timings are adhered to – failure to do this may result in poor conception rates.
Prices per animal will vary but will include all meds used and the vet’s time.
Please get in contact with your routine vet to find out how synchronisation could work for your herd.
Written By Claire Rudd, Veterinary Surgeon
